Monitoring method of a temperature of winding of electric rotating machinery is evaluated from the resistance value of the winding of electric rotating machinery have hitherto known. There is a method of using the sensor as other methods, such as a temperature measuring resistor or a thermocouple, is arranged near the winding, thereby to measure the temperature.
The method of the insulation diagnosis of winding of electric rotating machinery measures the size and frequency of the partial discharge pulse generated are hitherto known. There is a method of detecting a partial discharge signal by using the static electric coupling of one specified phase and the other method is to detect a pulsating current signal by a high-frequency current transformer are known.
The method of detecting abnormal state of gas in the housing of electric rotating machinery is known. There is a method of extraction of gas in case, and measurement with macro analysis device.
The following three Patent Documents are known as disclosing spectroscopy analysis methods:
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 06-288922
Patent Document 2: Japanese Patent Application Laid-Open Publication No. 07-198612
Patent Document 3: Japanese Patent Application Laid-Open Publication No. 08-201361